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United States Patent | 5,635,654 |
Hebsur ,   et al. | June 3, 1997 |
A particulate reinforced NiAl-AlN composite alloy has a NiAl matrix and greater than about 13 volume percent fine particles of AlN within the matrix. The particles preferably have a diameter from about 15 nanometers to about 50 nanometers. The particulate reinforced NiAl-AlN composite alloy may be prepared by cryomilling prealloyed NiAl in liquid nitrogen using grinding media having a diameter of from about 2 mm to about 6 mm at an impeller speed of from about 450 RPM to about 800 RPM. The cryomilling may be done for a duration of from about 4 hours to about 20 hours to obtain a cryomilled powder. The cryomilled powder may be consolidated to form the particulate reinforced NiAl-AlN composite alloy. The particulate reinforced alloy can further include a toughening alloy. The toughening alloy may include NiCrAlY, FeCrAY and FeAl.
Inventors: | Hebsur; Mohan G. (North Olmsted, OH); Whittenberger; John D. (North Olmsted, OH); Lowell; Carl E. (Berea, OH) |
Assignee: | The United States of America as represented by the Administrator of the (Washington, DC) |
Appl. No.: | 238767 |
Filed: | May 5, 1994 |
Current U.S. Class: | 75/244; 75/249; 419/13; 419/32; 419/33; 977/DIG.1 |
Intern'l Class: | C22C 021/00; B22F 003/00 |
Field of Search: | 75/245,249,244 419/33,13,32 |
4619699 | Oct., 1986 | Petkovic-Luton et al. | 75/252. |
4961905 | Oct., 1990 | Law et al. | 420/460. |
Bowman, Randy R., "Influence of Interfacial Characteristics on the Mechanical Properties of Continuous Fiber Reinforced NiAl Composites," Mat. Res. Soc. Symp. Proc., vol. 273, pp. 145-155. Hebsur, M. G. et al., "Microstructure/Property Relations in Aln and Al.sub.2 O.sub.3 Particulate Strengthened NiAl," Mat. Res. Soc. Symp. Proc., vol. 288, pp. 1111-1116. Bowman, Randy et al., "Unresolved Technical Barriers to the Development of a Structurally Viable Al.sub.2 O.sub.23 /NIAL Composite," HITEMP, NASA-CP-19117, 1993. Luton, M.J. et al., "Cryomilling of Nano-Phase Dispersion Strengthened Aluminum," Mat. Res. Soc. Symp. Proc., vol. 132, 1989, pp. 79-86. Whittenberger, J. D. et al., "Preliminary investigation of a NiAl composite prepared by cryomilling," J. Mater. Res., vol. 5, No. 2, Feb. 1990, pp. 271-277. Aikin, B.J.M. et al., "Reproducibility of NiAl Cryomilling," Mech. All. for Struct. App., Proc. 2nd Intl. Conf. Struct. Appl. Mech. All., Sep. 20-22 1993, pp. 283-290. Whittenberger, J. D. et al., "1300 K compressive properties of a reaction milled NiAl-AlN composite," J. Mater. Res., vol. 5, No. 12, Dec. 1990, pp. 2819-2827. Lowell, Carl E. et al., "Cyclic Oxidation Resistance of a Reaction Milled NiAl-AlN Composite," Mat. Res. Soc. Symp. Proc., vol. 194, 1990, pp. 355-360. Whittenberger, J. Daniel, "Characteristics of an elevated temperature AlN particulate reinforced NiAL," Structural Intermetallics, Oct. 1993, pp. 819-828. |
TABLE 1 ______________________________________ CHEMICAL COMPOSITION OF MELTSPUN AND CRYOMILLED Ni55Al MATRIX 2nd Phase ELEMENTS WT. % COMP. Al vol. % MATERIAL Ni Al N O AT % AIN Al.sub.2 O.sub.3 ______________________________________ Meltspun 63.2 36.7 -- .007 54.8 -- -- Ni55Al Cryomilled 60.0 32.7 6.6 .518 49.4 32.1 1.4 Powder HP + HIP 60.6 31.6 6.6 .52 48.2 32.1 1.4 NiAl-30AIN ______________________________________